Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The parameter descriptions contradict the tool purpose: 'url' is described as 'HTTPS URL to normalize or cite' rather than to fetch, and several unrelated params (ref, city, feed, json, path, zone, query) appear with no explanation of how they relate to web-fetch. This is misleading about the tool's actual behavior.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The main description is a single concise sentence, front-loaded with the key action. However, the schema includes many unnecessary-looking optional parameters that clutter the overall tool definition.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The tool does not state which parameters are needed, what a successful call returns, or how errors are reported. With 9 optional parameters and no required ones, an agent cannot reliably know how to invoke it, especially since the url parameter description is inconsistent with the tool's purpose.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Although every parameter has a description, most seem copy-pasted from other domains and do not clarify how they are used by web-fetch. For example, 'zone' is 'IANA timezone name' and 'query' is 'Search text; discarded after the length check', which do not align with a URL fetch tool.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a concrete action and object: 'HTTP status and content type for a public URL. Body discarded.' This is enough to understand the core purpose, though it does not explicitly say 'fetch'.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No alternative tools or conditions are mentioned. The only hint is that the body is discarded, implying it is for header/status checks, but this is not an explicit usage guideline.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.